[prawn]

OK, what about if our supermarkets are actually really tall buildings, and the drones glide down from the distribution platform on the top floor...

[falcor84]

That sounds pretty much the same as existing "catolog stores"[0] like Argos[1] (although your idea is probably a bit more automated).

[0] https://en.wikipedia.org/wiki/Catalog_merchant

[1] https://en.wikipedia.org/wiki/Argos_(retailer)